Big turbo, do I really need it?
Thread Starter
Teching In
Joined: Jun 2004
Posts: 9
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Big turbo, do I really need it? I'm thinking about going turbo and need a little advice. You know, the kind that doesn't require $5,000. 
I'll be doing the work myself and I know the basics of how a turbo works and how they install. I've been pricing out turbos and T70's are up there, actually almost all turbos are up there. I don't want to run more than 6psi and therfore don't want to spend the extra cash on something I won't need. Can I use two turbos, about the size that would supply a 3.0L engine, (3.0L plus 3.0L = more than 5.7L?) and be fine to run 5 or 6 psi? Am I correct in thinking that a turbo is a turbo is a turbo, it just depends on how much psi you want to slam into your engine or am I out to lunch? I'm even looking into getting two old turbo's off a 5cyl mercedes and replacing the seals and bearings and slapping those on. Good idea, or bad idea? Any help that anyone can supply is much appreciated....thanks for reading guys.
I'll be doing the work myself and I know the basics of how a turbo works and how they install. I've been pricing out turbos and T70's are up there, actually almost all turbos are up there. I don't want to run more than 6psi and therfore don't want to spend the extra cash on something I won't need. Can I use two turbos, about the size that would supply a 3.0L engine, (3.0L plus 3.0L = more than 5.7L?) and be fine to run 5 or 6 psi? Am I correct in thinking that a turbo is a turbo is a turbo, it just depends on how much psi you want to slam into your engine or am I out to lunch? I'm even looking into getting two old turbo's off a 5cyl mercedes and replacing the seals and bearings and slapping those on. Good idea, or bad idea? Any help that anyone can supply is much appreciated....thanks for reading guys. 
TECH Fanatic
Joined: Sep 2003
Posts: 1,937
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From: "Tr"Asheville
...well I was typing up some info for you but instead just go read Jose's site...
http://www.forcedinductions.com/help.htm
Keep in mind if you run 2 turbo's you will need 2 of everything, 2 wategates, 2 BOV's (if you use them) etc. which will add to the cost. When you said the price of the T70 was UP there, what is UP there to you? May know where you can get it cheaper then what your finding, like i said depending on what UP there is for you
-Sly
http://www.forcedinductions.com/help.htm
Keep in mind if you run 2 turbo's you will need 2 of everything, 2 wategates, 2 BOV's (if you use them) etc. which will add to the cost. When you said the price of the T70 was UP there, what is UP there to you? May know where you can get it cheaper then what your finding, like i said depending on what UP there is for you
-Sly
TECH Enthusiast
Joined: Jan 2004
Posts: 742
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From: Cincinnati, OH
The used and rebuilt twins would be about the same as a decent sized single (60 & above), but might just cost more. Rebuilding costs, twin headers, twin DPs, twin WG's and BOV's-I say go with the single. The plumbing would be more simple, as well. JMO, but I've been working with turbos for quite awhile now, so take that into account. 
i think your going about it the wrong way. You need to find the right size for your application. Id suggest something like a T60-1 (or somewhere around a 60mm turbo)
but what i tell everybody if your going to go FI go all the way, its alot simpler and cheaper to do heads, cam and bolt ons if your power goals are small (below 500rwhp) as a good package can get you in the 470rwhp. So unless you plan on making big power stay simple
but what i tell everybody if your going to go FI go all the way, its alot simpler and cheaper to do heads, cam and bolt ons if your power goals are small (below 500rwhp) as a good package can get you in the 470rwhp. So unless you plan on making big power stay simple
Launching!
Joined: Jan 2004
Posts: 249
Likes: 2
From: sarasota, fl
Originally Posted by slyws6
Keep in mind if you run 2 turbo's you will need 2 of everything, 2 wategates, 2 BOV's (if you use them) etc.
on a twin turbo car, both intake tracts eventually join into one before the throttle body with a backwards Y.........if you put the BOV after the Y, you only need one.
I am confused...why is everyone telling this guy to go with a 60 series or T70 turbo. I am currently running a single turbo kit on my Z. The kit that I have used a 62-1 turbo as the base turbo. The dyno graphs of cars using that turbo ran out of steam at 5K rpm. When I say "ran out of steam", I mean there was a huge torque peak and then equally huge dropoff. Therfore, I opted to go with a T71GTQ. My car made 560rwhp (using this as the baseline because it represents the only before/after pulls where a direct comparison could be made) I dynoed with that unit @ 12psi. I switched to a T76 GTS unit in anticipation of installation a 427 Darton Motor. I currently have it on my stock displacement motor while the Darton is being built. I dynoed the car just for grins and it made 600rwhp/598rwtq (same dyno that it made 560rwhp @ 12psi) at the same boost level and no additional tuning (hell the dyno graph even shows some wheel slip). It improved 40rwhp and 60rwtq. I also noticed no change in spool up time. It makes 6psi by 2,500rpm and 12psi by 3,200rpm.
20/20 hindsight would never recommend that anyone go any less than a T76 on a 346CI motor. It will make decent power at low boost and provide a great deal of updside. Plus its not that much more than a 62-1 or a T70, costwise. Take it from someone who is about to buy his third turbo. Do it right the first time. Dimensionally, my T76 bolted in the same location and didn't seem much bigger than my T71.
20/20 hindsight would never recommend that anyone go any less than a T76 on a 346CI motor. It will make decent power at low boost and provide a great deal of updside. Plus its not that much more than a 62-1 or a T70, costwise. Take it from someone who is about to buy his third turbo. Do it right the first time. Dimensionally, my T76 bolted in the same location and didn't seem much bigger than my T71.
